Ignition apparatus



E m w x 2 L. o, w wm W 1 n N N U 6 f Au Eosc e 2, 7 VM; n H J v EN f T W 4 UU R N@ WY d@ J. T. FITZSIMMONS IGNITION APPARATUS Filed March l5, 1949 Sept. 9, 1952 Patented Sept. 9, 1952 UNITED STATES PATENT GFFICE IGNITION APPARATUS John T, -Fitzsimmons,rdeceased, late of Anderson,

Ind., by Edna M Fitzsimmons, executrix, Anderson, Ind., assi'gnor to General Motors 'Corporation, Detroit, Mich., a corporation of Michi- Application March 15, 1949, Serial No. 81,433` y (Cl. Z110-31) 4 Elaims. 1

This invention relates 'to improvements iin bearing structures'for an ignition timer ior Vinternal combustion engines, and more 'particularly to bearing structures for the type of timer having automatic means responsive to engine 'intake suction for varying the timing of the ignition. An ignition timer of 'this vtype is generally provided with a rotatable circuit vbreaker supporting plate which is adjustable 'by engine lsuction responsive means about an 'axis lconcentric with the axis of rotation of the ignition timer cam. The rotatable plate is provided with a hub or bearing 'sleeve member which has a running nt within a bearing provided by a stationary plate. Since a running fit is required, there `is a slight clearance between the bearing surfaces. The rotatable plate carries a circuit breaker device including `a lever having a rubbing block which is actuated by ra cam during rotation thereof. When the rubbing block isstruck by the cam, the rotatable plate is 'urged to one -s-ide each time the cam strikes the rubbing block. Consequently, there is chattering between the bearings and the timing of the ignition .may be erroneous.

An `object 'of the present invention is to eliminate kchattering without appreciably reducing freedom of rotative movement of the circuit breaker plate. This object is accomplished by a spring interposed 'directly between the bearing members provided Vby'theixed and rotary plates and so located .relativet'c the circuit breaker that the :bearing member ofthe circuit 'breaker Yplate is urged against the bearing member'of the xed plate in a direction which :is the same as 'that in which the circuit breaker plate is urged when the lobes of the 'cam'strike the .rubbing .block of the circuit breaker lever. By locating the spring directly between the bearing members, cooking of the'movable 'bearing relative to the iixed bearing is prevented and interference with freedom of .rotary movement of the circuit Abreaker plate is minimized.

Further objects andi advantages of the Apresent invention will be apparent .from the ifollowing description, reference being had to the a'ccompanying drawings wherein the .preferred embodiment'of the invention 'is'clearly shown.

In the drawings:

-Fig. 1 Tis a plan view o'fan ignition timer which ifnelu'des ian embodiment o'f vthe fpresent invention.

' 2 is a side 'view :partly in section on line 2=2 of Fig. 1.

Figs. 3 and 4 are 'sectional'views 'takenrespectively yon lines 3-3-fand -4"4 eifrig.' v1.

Fig. 5 is an enlargement or` a vportion of Fig. 2.

Fig. 6 is a fragmentary sectional View on line 6--6 of Fig. 5.

Fig. 7 is a View in the direction .of arrow 1 of Fig. 6.

Referring to Figs. 1 and 2, 20 designates a timer housing having a bearing 2| which .supports for rotation an engine .dri-ven shaft 22 upon which is mounted a timer cam 23 which is drivingly connected with the shaft 22 .by a device 24 which, in response to speed, change-s the angular relation between .the vcam 23 and the engine driven shaft 22. The cam 23 lsupports and drives a rotor 25 vcarrying a conducting member (not shown) which sweeps past and distributes spark impulses `to terminals (not shown) supported by a distributor cap or =cover 26.

A stationary plate 21, supported within the housing 20, has three ears 28 each of which :has a threaded aperture to receive the threaded end of -a screw 29 which secure the plate 21 in position within the housing. Two of .the screws 29 secure to the housing 20 brackets .30 each hingedly supporting a clamp spring 3l which secures the cap 25 upon the housing 20.

The stationary lplate -21 is provided with a central opening defined by an annular flange 32 having an internal, cylindrical bearing surface concentric with the :bearing 2|. This flange 32 has an arcuate recess 33 (Fig. `6) extending inwardly from the bearing surface -of ange 32 and receiving a leaf spring 34 having a .main portion 35 and a pair of spaced tongues 36 on one side edge thereof. The spring 34 is initially at, but when it is placed in the recess 33 and between the hub 31 of a circuit breaker plate 38 and the ilange -32, its mid-portion .presses in the direction of arrow (Fig. 6.) against the hub 31 and its end portions press inthe direction of arrows y against the flange 32 thus urging the hub 31 always to the left in Fig. 6 for a purpose to be described. Hub 31 is retained within the bearing `iiange 32 by one or more resilient metal G-washers 39 received Vby a groove 40 in hub -31. The tongues 36 extend downwardly between the ends of C-washers 39 and the main portion 35 of the spring 34 may gravitate into contact with the'uppermost C-washer'as shownin lFigs. 45 and '7. The plate -38 is provided 'with a'plurality of apertures 4I (Fig. A5) afd-jacent its periphery which receive Athe Shanks 542 :of lbearing 'buttons 43 which are 'attached to 'the 'plate 3B -bystaking the shanks* slightly in a 'plurality Jo'f vplaces as shown Yatv 'c4 VFig. '5. The lower 'ends of the buttons are provided with convex surfaces 45 which contact with the upper face of the stationary plate 21. By this arrangement friction between the buttons and the lower plate is reduced to a minimum. The lower ends of the buttons extend through apertures provided by a felt washer 46 saturated with lubricant which lubricates the upper face of the stationary plate 21.

To the movable plate 38 there is attached a stud 50 received by a hole 5| in felt washer 48 and an arcuate slot 52 in plate 21. After assembling the plate 38 with theplate 21, a nonmetallic bearing washer 53, a cupped spring washer 54 and one or more fiat spring washers 55 are placed around the stud 50 and a C-washer 56 is placed in a groove 51 of the stud 58 and it is deformed in a manner such as to prevent accidental removal. The spring washers cause the buttons 43 to press against the plate 21 thus fixing the location of the plate 38 relative to the housing 20. The arcuate slot 52 limits the degree of angular movement of the upper plate 38 relative to the lower plate 21.

As stated before, the spring 35 urges the hub 31 of plate 38 left in Figs, 5 and 6. This direction is vertically down as viewed in Fig. l. Therefore the hub 31 engages the flange 32 in the immediate vicinity of the circuit breaker rubbing block 60 attached to circuit breaker lever 5l. Therefore, when the lobes of cam 23 strike the rubbing block 60, and tends to urge the plate 38 left in Fig. 2 or down in Fig. l, there is no shifting of the plate 38 since all bearing clearance has been taken up in said direction. In other words, the movable plate 38 is always being urged by spring 34 in that direction which is the same as the direction in which the movable plate is urged when the lobes of 'the cam 23 strike the rubbing block. Because the spring 34 is located directly between the bearing hub 31 of plate 38 andthe bearing iiange 32 of plate 21 and is substantially coextensive vertically with these bearing members, there is no tendency to cock the bearing hub 31 relative to the bearing iiange 32. The shanks of bearing buttons 43 are staked lightly against the plate 38 as indicated at 44 in Fig. 5 and the shank of stud 50 is welded to plate 38 thereby avoiding riveting operations which might cause such distortion of the plate 38 that, when its three buttons 43 are drawn against the plate 21 by spring washer 54, plate 38 would be non-parallel to plate 21 and the bearing hub 31 would be cocked or located obliquely relative to the bearing flange 32. Therefore interference with freedom of rotation of plate 38 has been minimized. Y

The circuit breaker lever 8| is pivotally mounted on a stud 62 attached to the movable plate 38 and carries a contact 64 engageable with a stationary contact 65 attached to a bracket 6G. The lever is pressed toward contact closing position by a leaf spring 61. As will be understood the contacts are connected in the usual ignition circuit, not

4 connected to a bearing (Fig. 3) attached to the movable plate 38. The shell 12 supports a sleeve 11 carrying a bushing 18. A compression spring 19 is disposed between a shoulder provided by the bushing and a cup-shaped washer 80 attached to the diaphragm.r Bushing 18 is connectible with a pipe (not shown) connected with the engine intake.

shown, so that the circuit is periodically broken at the contacts by the cam 23 as the-shaft 2l rotates. Y l

The movable or upper plate 38 is 'rotated rela- Y tive tothe stationary plate by a device 1i! respon- While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted. Y

What is claimed is as follows:

l.A An ignition timer comprising a housing, an engine driven rotary cam supported by the housing, a xed plate attached to the housing and providing a bearing concentric with the axis of the cam, a rotatable plate supported laterally by the fixed plate and having a bearing received by the fixed plate bearing, a circuit breaker attached to .fthe rotatable plate and including fixed and movable contacts and a movable member carrying the movable contact, a spring urging the movable member into contact closing posiltion and a rubbing block carried ibv the movable member engageable with the cam on one side thereof, and a leaf spring disposed in a recess in one of the bearings on a radial line through said rubbing block and interposed between the fixed and movable bearings, said leaf spring being of a length greater than the circumferential length of the recess for causing the spring to bulge `outwardly of the recess for causing the leaf spring to act as a cushion between the fixed an-d movable bearings to take up impulses created by the cam striking the rubbing block. Y

2. An ignition timer comprising a housing, an engine driven rotary cam supported by the housing, a i-lxed plate attached to the housing and providing a -central bearing concentric with the axis of the cam, a rotatable plate supported laterally by the fixed plate and having a centrally located bearing journalled within the fixed plate bearing, a circuit breaker attached to the rotatable plate and including fixed and movable contacts and a movable member carrying the movable contact and a spring urging the movable member into contact closing position and a rubbing block carried by the movable member and engageable with the cam on one side thereof; and a spring located in a recessprovided by the fixed plate bearing and located adjacent to that side of the vcam opposite to thatside of the camwhich strikes the, rubbing block and operable. to .urge

the rotatable lplate bearing against the Xed plate bearing Vtransversely ofthe bearing axes in substantially the same direction as that which ocurs when a lobe of the cam strikes the rubbing b ook.

3. VAn ignition timer comprising a housing, :an engine driven rotary cam supported `by the housing, a xed plate attached to the housing `and providing a central ,bearing concentric with the axis of the cam, a rotatable plate supported laterally by the xed plate and having' a centr-ally located bearing ljournalled within the fixed plate bearing, a circuit breaker attached to the, rotatable plate and including fixed and 'movable contacts and a movable member carrying Vthe while the other end of the link passes through movable contact and a spring urging the movable member into contact closing position and arubbing block carried by the movable memberand between the xed and movable bearing and ad- :jacent to that side of the cam opposite to that side of the cam which strikes the rubbing block, said spring having its ends engaging the fixed plate bearing and its mid-portion engaging the rotatable plate bearing and operable to urge lthe rotatable plate bearing against the fixed plate bearing transvjersely of the bearing axes in substantially the same direction as that which occurs when a lobe of the cam strikes the rubbing block.

4. An ignition timer according to claim 3 in which an arcuate recess provided by the fixed plate bearing extends through it, in which the rotatable plate bearing extends from the rotatable plate through the fixed plate bearing and beyond it, in which there is a member attached to that portion of the rotatable plate bearing extending beyond the xed plate bearing and in 6 Awhich Ithe leaf spring is confined edgewise between the rotatable plate and the member lattached to the rotatable plate bearing.

EDNA M. FITZSIMMONS, Eeowtri of the Estate of John T. Fitzsimmons,

Deceased.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 15 1,797,862 Graham et al Mar. 24, 1931 2,348,236 Arthur May 9, 1944 2,471,318 Fitzsimmons et al. May 24, 1949 2,487,231 Fitz-simmons Nov. 8, 1949 2,489,775 Haubert Nov. 29, 1949 

